The present invention relates to the field of pharmaceutical orally ingested solid dosage forms.
One challenge in pharmacy is that many people are unwilling and/or unable to swallow tablets, capsules or other traditional solid dosage forms.
One approach suitable for persons who cannot or will not swallow a tablet or capsule is the use of effervescence.
Effervescence can be defined as the evolution of bubbles of gas in a liquid. As set forth in chapter 6 of Pharmaceutical Dosage Forms: Tablets Volume I, Second Edition. A. Lieberman. ed. 1989, Marcel Dekker, Inc. (the entirety of which is hereby incorporated by reference), effervescent mixtures have been known and used medicinally for many years. As discussed in this text, and as commonly employed, an effervescent tablet is dissolved in water to provide a carbonated or sparkling liquid drink. In such a drink the effervescence helps to mask the taste of medicaments. However, the use of effervescent tablets to prepare a beverage including medicaments, is not convenient. It requires prepatory steps before administration of the drug and also requires the presence of a suitable mixing container.
In a departure from the traditional use of effervescence, U.S. Pat. No. 4,639,368 describes a chewing gum containing a medicament capable of absorption through the buccal cavity and a composition capable of generating carbon dioxide as a taste masking agent. The gum may optionally include a further taste bud desensitizing compound. Unfortunately there are substantial disadvantages inherent in such a gum based delivery system. Many medicants are not suited for buccal absorption. Gums are difficult to prepare. Because of braces or other dental work, many persons are not permitted to chew gum. Furthermore, the medicament must be released into solution in the saliva. Thus the full taste of the medicament is perceived, subject only to the taste masking effect. If the flavor and/or the effervescent taste masker are insufficient and/or fade prior to the full release of medicament, the patient will be left with a gum having an objectionable taste. Gums also leave residues which must be disposed of.
Effervescent tablets have also been used in the dental area. Westlake, U.S. Pat. No. 1,262,888, Howell, U.S. Pat. No. 3,962,417 and Aberg U.S. Pat. No. 4,753,792 disclose effervescent dentifrice tablets adapted to foam in the mouth of a patient so as to provide a tooth cleansing action.
Chavkin U.S. Pat. No. 4,613,497 discloses a water foamable pharmaceutical composition incorporating an effervescent agent, a polysaccheride gum, and a gelling salt together with a pharmaceutically active ingredient. The composition is not intended to immediately disintegrate but rather to form a stable foam in the patient's stomach or other body cavity so that the active ingredient is gradually released from the foam. Sparks, U.S. Pat. No. 4,940,588 describes microparticles or "pharmasomes" which are adapted to provided "controlled release", i.e., a very slow release of the active ingredient from within the microparticles. These controlled-release particles are said to provide a "taste masking" action, and to resist degradation by chewing. However, such particles cannot be used where rapid dissolution of the drug is required.
Despite these and other efforts towards developments of suitable dosage forms, there have been unmet needs heretofore for improved dosage forms and for improved methods of administration of systematically distributable pharmaceutical ingredients such as drugs, vitamins and the like.